// $Id: SerialByteSource.java,v 1.4 2003/10/07 21:46:01 idgay Exp $

/*									tab:4
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 * All rights reserved.
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 * hereby granted, provided that the above copyright notice, the following
 * two paragraphs and the author appear in all copies of this software.
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 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
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 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
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 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
 *
 * Copyright (c) 2002-2003 Intel Corporation
 * All rights reserved.
 *
 * This file is distributed under the terms in the attached INTEL-LICENSE     
 * file. If you do not find these files, copies can be found by writing to
 * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300, Berkeley, CA, 
 * 94704.  Attention:  Intel License Inquiry.
 */

package tools.packet;

import java.util.*;
import java.io.*;
import javax.comm.*;

/**
 * A serial port byte source, with extra special hack to deal with broken
 * javax.comm implementations (IBM's javax.comm does not set the port to raw
 * mode, on Linux, at least in some implementations - call an external program
 * (tinyos-serial-configure) to "fix" this)
 */
public class SerialByteSource extends StreamByteSource implements
		SerialPortEventListener {
	private SerialPort serialPort;
	private String portName;
	private int baudRate;

	public SerialByteSource(String portName, int baudRate) {
		this.portName = portName;
		this.baudRate = baudRate;
	}

	public void openStreams() throws IOException {
		CommPortIdentifier portId;
		try {
			portId = CommPortIdentifier.getPortIdentifier(portName);
		} catch (NoSuchPortException e) {
			throw new IOException("Invalid port. " + allPorts());
		}
		try {
			serialPort = (SerialPort) portId.open("SerialByteSource",
					CommPortIdentifier.PORT_SERIAL);
		} catch (PortInUseException e) {
			throw new IOException("Port " + portName + " busy");
		}

		try {
			serialPort.setFlowControlMode(SerialPort.FLOWCONTROL_NONE);
			serialPort.setSerialPortParams(baudRate, SerialPort.DATABITS_8,
					SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);

			serialPort.addEventListener(this);
			serialPort.notifyOnDataAvailable(true);
		} catch (Exception e) {
			serialPort.close();
			throw new IOException("Couldn't configure " + portName);
		}

		// Try & run external program to setup serial port correctly
		// (necessary on Linux, IBM's javax.comm leaves port in cooked mode)
		try {
			Runtime.getRuntime().exec("tinyos-serial-configure " + portName);
		} catch (IOException e) {
		}

		is = serialPort.getInputStream();
		os = serialPort.getOutputStream();
	}

	public void closeStreams() throws IOException {
		serialPort.close();
	}

	public String allPorts() {
		Enumeration ports = CommPortIdentifier.getPortIdentifiers();
		if (ports == null)
			return "No comm ports found!";

		boolean noPorts = true;
		String portList = "Known serial ports:\n";
		while (ports.hasMoreElements()) {
			CommPortIdentifier port = (CommPortIdentifier) ports.nextElement();

			if (port.getPortType() == CommPortIdentifier.PORT_SERIAL) {
				portList += "- " + port.getName() + "\n";
				noPorts = false;
			}
		}
		if (noPorts)
			return "No comm ports found!";
		else
			return portList;
	}

	Object sync = new Object();

	public byte readByte() throws IOException {
		// On Linux at least, javax.comm input streams are not interruptible.
		// Make them so, relying on the DATA_AVAILABLE serial event.
		synchronized (sync) {
			while (is.available() == 0) {
				try {
					sync.wait();
				} catch (InterruptedException e) {
					close();
					throw new IOException("interrupted");
				}
			}
		}

		return super.readByte();
	}

	public void serialEvent(SerialPortEvent ev) {
		synchronized (sync) {
			sync.notify();
		}
	}

}
